Tennis Industry magazine


Playtest: Volkl V-Rex

By Greg Raven

V-Rex is a new monofilament polyester string from Völkl. According to Völkl, V-Rex is a unique co-polyester developed specifically for today’s serious aggressive player who demands precise control and reliable durability. Due to a patented manufacturing process, Völkl says that V-Rex maintains tension exceptionally well, which ensures its unique performance longer than conventional polyester strings. And where conventional polyester strings can feel harsh, Völkl tells us that V-Rex offers a soft yet elastic feel.

Volkl V-Rex

V-Rex is available in 16L in yellow only. It is priced from $8 per set, and $120 for reels of 770 feet. For more information or to order, contact Völkl at 800-264-4579, or visit Völkl on the web.

In the lab

We tested the 16L (1.27 mm) gauge V-Rex. The coil measured 41’11”. The diameter measured 1.27 mm prior to stringing, and 1.23 mm after stringing. We recorded a stringbed stiffness of 71 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 × 18 pattern) on a constant-pull machine.

After 24 hours (no playing), stringbed stiffness measured 66 RDC units, representing a 7 percent tension loss. Our control string, Prince Synthetic Gut Original Gold 16, measured 78 RDC units immediately after stringing and 71 RDC units after 24 hours, representing a 9 percent tension loss. V-Rex added 15 grams to the weight of our unstrung frame.

The string was tested for five weeks by 31 USRSA playtesters, with NTRP ratings from 3.0 to 6.0. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. The average number of hours playtested was 23.8.

Out of the package, V-Rex feels and strings up like other polyesters, with low elongation during tensioning. Coil memory is about what you would expect, but blocked holes are no problem. The string has enough texture to it so that it doesn’t slip through your fingers when weaving the crosses. Thirteen of our playtesters rated it about the same or easier to install than their favorite string, while 18 rated it not as easy to install.

No playtester broke a sample during stringing, 13 reported problems with coil memory, 5 reported problems tying knots, and 3 reported friction burn.

On the court

According to our playtesters, Völkl V-Rex really stands out in our Control, Resistance to Movement, and Durability categories. In the Control category, our playtesters gave V-Rex second place of all the strings we’ve tested to date. In Resistance to Movement, they gave V-Rex third place of all the strings we’ve ever tested. And for Durability, they gave V-Rex fourth place of all the strings we’ve ever tested, with 25 of our playtesters also saying that V-Rex has better or much better durability than other strings of similar gauge. What’s more, our playtesters think V-Rex is well above average in Spin Potential, and Holding Tension, and above average in Power. These ratings were good enough to give Völkl V-Rex an overall above average score.

Only two playtesters broke the test sample, one at 18 hours, and one at 70 hours.


Völkl V-Rex is yet another solid option for players seeking the durability that comes from using a polyester string, as along with that durability comes control, resistance to movement, spin potential, and power. This is a great combination for any string, and more than a third even found the playability better than average. If you have customers who take a full swing at the ball and need a string that can hang in there, Völkl V-Rex might be just the string they need.

Playtester comments

“Much better than most others polys. Very responsive for a poly. I would even recommend it over the present leading poly strings.” 5.0 male all court player using Babolat Pure Drive Zylon strung at 50 pounds CP (Forten Kevlar / Gosen Polylon 17/16)

“I love this string. Coil memory is not a minus, for it strings up quick and clean. Tension is still near where I strung it, 25 hours of play and a month later. Lots of pop, great power, but under control, even with my oversize frame. Still feels great.” 3.0 male all court player using Volkl Catapult VI OS strung at 58 pounds LO (Gamma XP Pro 17)

“I like this string. It hits great. I will use it when I find out the name.” 4.0 male all court player using Wilson H5 strung at 55 pounds CP (Wilson NXT Max 16)

“This is a string I love to play with. Stiff stringbed, string doesn’t move. Great control. Lets me supply the power I need. Solid feel. Great. Let me know what it is!” 4.5 male all court player using Wilson H Blaze strung at 70 pounds CP (Luxilon Alu Power 16L)

“Overall pleased with the string. Really had good “pop” on flat serves and still had plenty of kick on spin serves.” 3.5 male serve-and-volleyer using Wilson Pro Staff 6.5 strung at 62 pounds CP (Wilson Sensation 16)

“A good all-around string.” 5.5 male all court player using Prince Turbo Shark strung at 60 pounds CP (Kevlar/gut 16)

“I like this string right from the start. I feel I can do anything. The only setback was tension loss after awhile. Some members used my racquet as well, and they liked it very much. This is a good string. No pain in the elbow as with many poly strings.” 5.5 male all court player using Head Liquidmetal Rave strung at 54 pounds CP (Head IntelliTour 17)

“This string plays slightly better than most polyester strings I’ve tried in the past, but still maintains most of the qualities of a poly. Excellent control, durability, and resistance to movement, but comfort and feel are below average. I would like to try this string in a hybrid with a softer synthetic gut in the crosses. Could be a winner in that setup.” 4.0 male all court player using Volkl V1 Classic strung at 58 pounds LO (Babolat Tonic 16)

“This string has a very comfortable feel from the first hit. Tension holds up nicely. Nice combination of power and feel. Stringing was slightly more problematic. It was stiff enough to make knots more difficult. Not a flexible string during installation.” 5.0 male all court player using Prince More Control DB 800 strung at 63 pounds LO (Prince 16)

“This string plays more like a synthetic gut than a poly. I am surprised at the playability and power it has. It maintains tension very well and does not move at all in a 16×18 pattern. Depending on price, I would consider using this string.” 5.0 male baseliner with heavy spin using Wilson Pro Staff ROK strung at 68 pounds LO (Luxilon Ace / Babolat VS Tonic 18)

“This monofilament feels very stiff out of the package, but is both fast and easy to string, with little to no coil memory and very short pulls on the tension head. My first reaction on court was that it has less “pop” than my current string, but I’d adjust the tension to compensate if I tried it again. It has significantly better ball grad than my current string. I hit my best slices and topspins ever, even better than hybrids I’ve tried. There is absolutely no string movement for quite a while, and amazingly, the string has an unexpectedly soft feel at impact. This string should sell well to young power hitters who want a soft feel, great grab, spin, and durability.” 3.5 male all court player using Gamma Diamond Fibre F-9.0 strung at 65 pounds LO (Gamma Live Wire XP 17)

“This string has a great combination of durability (its strongest feature) with comfort and control. After 20 hours of play, the strings have yet to end up out of place. After stringing, I was expecting it would be hard on my arm, but I’m pleasantly surprised.” 3.5 male all court player using Head Liquidmetal Radical OS strung at 60 pounds CP (Babolat VS Touch 16)

“I found nothing special about this string — a standard poly with good durability and control, but no feel. There are plenty of other polys I like more Stringing was easy, no problems.” 4.0 male all court player using Wilson Hyper Pro Staff 6.0 strung at 60 pounds LO (Wilson Natural Gut 17)

“This string is definitely stiffer than what I am used to playing. I strung it a few pounds lower than normal to give it a little more feel. It plays slightly better than anticipated, considering I am used to a softer string. I have no negatives on this string for hard hitters. I admit I feel I lost a little power due to its elasticity and responsiveness. I would recommend it for regular string breakers.” 5.0 male all court player using Prince More Balance 950 strung at 58 pounds CP (Wilson Sweet Perfection 17)

“I experienced no problems stringing this sample, except for coil memory, which was noticeably more than that of other strings. Initially it took some time to become accustomed to the feel of the string in that it is exceptionally stiff and tends to increase vibration in the frame, which subsequently causes some arm soreness. Playability is significantly less compared to my normal string: however, over time I did become more accustomed to the limited feel. The strings never moved or notch during the entire test period. I would strongly recommend this string for heavy hitters who tend to use a lot of topspin and are interested in having an extremely durable string.” 4.5 male all court player using Fischer Pro Impact FT strung at 54 pounds LO (Gamma Live Wire 17)

“Seems likes another in a line of poly strings. The string is only okay playability-wise, because I’m always comparing each of these test samples against my normal string, which I like a lot, and I’m also somewhat biased toward multifilaments.” 4.5 male all court player using Head Liquidmetal Radical MP strung at 62 pounds LO (Tecnifibre NRG2 18)

“Relatively difficult to string, but this is a good choice for players who use huge amounts of spin, and for those who use control and feel. This string is not for recreational players, as power must be generated by the player’s technique. This string could be reliably recommended to frequent string breakers.” 4.5 male serve and volleyer using Wilson Hyper Hammer 2.3 strung at 66 pounds LO (Wilson Sensation 16)

“Solid string with good control, but it does lose tension.” 4.5 male all court player using Dunlop 300G strung at 60 pounds LO (Babolat Ballistic 16)

“Stiff feeling string, but not too bad to install.” 6.0 male all court player using Head Liquidmetal Instinct strung at 57 pounds LO (Head synthetic gut 16)

“For a polyester string, this has less buzzing than others I’ve tried. It holds tension longer, as well. Good for hard hitters but not for more elderly players. Not as comfortable or powerful as a good 17-gauge nylon.” 4.5 male all court player using Wilson Triad 4.0 strung at 60 pounds CP (Gamma Live Wire Professional 17)

“This string is okay. It’s good for those who can generate his own power off his swing. Being yellow, your opponent can lose the ball of the string. Durable.” 4.5 male all court player using Wilson Pro Staff 5.1 Surge strung at 60/58 pounds LO (Wilson Polylast / Wilson Stamina 17)

“Could not generate as much spin as with my normal string. Very durable.” 5.5 male all court player using Prince Tour Diablo Mid strung at 62 pounds LO (Luxilon Alu Power 16L)

“Good on ground strokes, but not as crisp on volleys. Stringbed softened with time, which seemed due to tension loss. Good string for baseline players with topspin, who break strings frequently.” 4.0 male all court player using Wilson Hyper Pro Staff 5.0 strung at 65 pounds LO (Dunlop Max Comfort 16)

“Played fairly well initially. Tension and resilience very short-lived.” 5.5 male all court player using Wilson Pro Staff Tour 90 strung at 58 pounds LO (Gosen Micro 17)

“This feels and plays as your typical poly string. My preference would have been to split this set in two and make a hybrid of it. For my style of play, this string is tiresome and tends to irritate my shoulder and elbow. It lacks the feel and playability I like in my string.” 3.5 male baseliner with moderate spin using Babolat Drive Z Max strung at 57 pounds CP (Bow Brand gut 16)

“Great control string, but boardy-stiff in play. Strings did not move at all. My strokes lacked depth when playing singles in cooler weather (50s). Not a string I would stock.” 4.0 male all court player using Wilson Hyper Pro Staff Surge strung at 56/54 pounds CP (Gamma Zo+ 16L)

“This string went dead after 18 hours.” 6.0 male all court player using Wilson nSix-One Tour strung at 53 pounds LO (Poly / gut 16)

“This poly-type string plays softer than some others I’ve used. It still doesn’t have the feel or comfort that I am accustomed to. Also, as the tension drops the stringbed just goes dead.” 4.5 male all court player using Volkl Catapult 3 Gen 2 strung at 55/53 pounds CP (BDE Performance 17)

“One of the better-playing poly strings, but that pinging sound is just too annoying. I could not recommend this string to anyone.” 4.0 male baseliner with heavy spin using Wilson Hyper Hammer 4.3 PH strung at 64 pounds LO (Tecnifibre X-One Biphase 17)

(Strings normally used by testers are indicated in parentheses.)


(compared to other strings)
Number of testers who said it was:
much easier 0
somewhat easier 4
about as easy 9
not quite as easy 18
not nearly as easy 0
(compared to string played most often)
Number of testers who said it was:
much better 0
somewhat better 4
about as playable 7
not quite as playable 17
not nearly as playable 3
(compared to other strings of similar gauge)
Number of testers who said it was:
much better 8
somewhat better 17
about as durable 6
not quite as durable 0
not nearly as durable 0
From 1 to 5 (best)
Playability 3.2
Durability 4.5
Power 3.3
Control 3.9
Comfort 2.7
Touch/Feel 2.8
Spin Potential 3.5
Holding Tension 3.5
Resistance to Movement 4.0

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About the Author

Greg Raven  is an associate editor for Tennis Industry magazine and technical writer. He is certified as a Master Racquet Technician by the U.S. Racquet Stringers Association. He can be reached via e-mail at, or through Facebook, LinkedIn, and Twitter. He plays tennis three to five days a week, and is turning into an avid cyclist.



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